/**
 * Find all possible combinations of k numbers that add up to a number n, given that only numbers from 1 to 9 
 * can be used and each combination should be a unique set of numbers.
 * Example 1:
 * Input: k = 3, n = 7
 * Output:[[1,2,4]]
 * Example 2:
 * Input: k = 3, n = 9
 * Output:
 * [[1,2,6], [1,3,5], [2,3,4]]
 */
/**
 * @author I321035
 *
 */
package problem216_Combination_Sum_III;